1 /* 2 * Virtual hardware watchdog. 3 * 4 * Copyright (C) 2009 Red Hat Inc. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 2 9 * of the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, see <http://www.gnu.org/licenses/>. 18 * 19 * By Richard W.M. Jones (rjones@redhat.com). 20 */ 21 22 #include "qemu/osdep.h" 23 24 #include "qemu/module.h" 25 #include "qemu/timer.h" 26 #include "sysemu/watchdog.h" 27 #include "hw/pci/pci_device.h" 28 #include "migration/vmstate.h" 29 #include "qom/object.h" 30 31 /*#define I6300ESB_DEBUG 1*/ 32 33 #ifdef I6300ESB_DEBUG 34 #define i6300esb_debug(fs,...) \ 35 fprintf(stderr,"i6300esb: %s: "fs,__func__,##__VA_ARGS__) 36 #else 37 #define i6300esb_debug(fs,...) 38 #endif 39 40 /* PCI configuration registers */ 41 #define ESB_CONFIG_REG 0x60 /* Config register */ 42 #define ESB_LOCK_REG 0x68 /* WDT lock register */ 43 44 /* Memory mapped registers (offset from base address) */ 45 #define ESB_TIMER1_REG 0x00 /* Timer1 value after each reset */ 46 #define ESB_TIMER2_REG 0x04 /* Timer2 value after each reset */ 47 #define ESB_GINTSR_REG 0x08 /* General Interrupt Status Register */ 48 #define ESB_RELOAD_REG 0x0c /* Reload register */ 49 50 /* Lock register bits */ 51 #define ESB_WDT_FUNC (0x01 << 2) /* Watchdog functionality */ 52 #define ESB_WDT_ENABLE (0x01 << 1) /* Enable WDT */ 53 #define ESB_WDT_LOCK (0x01 << 0) /* Lock (nowayout) */ 54 55 /* Config register bits */ 56 #define ESB_WDT_REBOOT (0x01 << 5) /* Enable reboot on timeout */ 57 #define ESB_WDT_FREQ (0x01 << 2) /* Decrement frequency */ 58 #define ESB_WDT_INTTYPE (0x11 << 0) /* Interrupt type on timer1 timeout */ 59 60 /* Reload register bits */ 61 #define ESB_WDT_RELOAD (0x01 << 8) /* prevent timeout */ 62 63 /* Magic constants */ 64 #define ESB_UNLOCK1 0x80 /* Step 1 to unlock reset registers */ 65 #define ESB_UNLOCK2 0x86 /* Step 2 to unlock reset registers */ 66 67 /* Device state. */ 68 struct I6300State { 69 PCIDevice dev; 70 MemoryRegion io_mem; 71 72 int reboot_enabled; /* "Reboot" on timer expiry. The real action 73 * performed depends on the -watchdog-action 74 * param passed on QEMU command line. 75 */ 76 int clock_scale; /* Clock scale. */ 77 #define CLOCK_SCALE_1KHZ 0 78 #define CLOCK_SCALE_1MHZ 1 79 80 int int_type; /* Interrupt type generated. */ 81 #define INT_TYPE_IRQ 0 /* APIC 1, INT 10 */ 82 #define INT_TYPE_SMI 2 83 #define INT_TYPE_DISABLED 3 84 85 int free_run; /* If true, reload timer on expiry. */ 86 int locked; /* If true, enabled field cannot be changed. */ 87 int enabled; /* If true, watchdog is enabled. */ 88 89 QEMUTimer *timer; /* The actual watchdog timer. */ 90 91 uint32_t timer1_preload; /* Values preloaded into timer1, timer2. */ 92 uint32_t timer2_preload; 93 int stage; /* Stage (1 or 2). */ 94 95 int unlock_state; /* Guest writes 0x80, 0x86 to unlock the 96 * registers, and we transition through 97 * states 0 -> 1 -> 2 when this happens. 98 */ 99 100 int previous_reboot_flag; /* If the watchdog caused the previous 101 * reboot, this flag will be set. 102 */ 103 }; 104 105 106 #define TYPE_WATCHDOG_I6300ESB_DEVICE "i6300esb" 107 OBJECT_DECLARE_SIMPLE_TYPE(I6300State, WATCHDOG_I6300ESB_DEVICE) 108 109 /* This function is called when the watchdog has either been enabled 110 * (hence it starts counting down) or has been keep-alived. 111 */ 112 static void i6300esb_restart_timer(I6300State *d, int stage) 113 { 114 int64_t timeout; 115 116 if (!d->enabled) 117 return; 118 119 d->stage = stage; 120 121 if (d->stage <= 1) 122 timeout = d->timer1_preload; 123 else 124 timeout = d->timer2_preload; 125 126 if (d->clock_scale == CLOCK_SCALE_1KHZ) 127 timeout <<= 15; 128 else 129 timeout <<= 5; 130 131 /* Get the timeout in nanoseconds. */ 132 133 timeout = timeout * 30; /* on a PCI bus, 1 tick is 30 ns*/ 134 135 i6300esb_debug("stage %d, timeout %" PRIi64 "\n", d->stage, timeout); 136 137 timer_mod(d->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + timeout); 138 } 139 140 /* This is called when the guest disables the watchdog. */ 141 static void i6300esb_disable_timer(I6300State *d) 142 { 143 i6300esb_debug("timer disabled\n"); 144 145 timer_del(d->timer); 146 } 147 148 static void i6300esb_reset(DeviceState *dev) 149 { 150 PCIDevice *pdev = PCI_DEVICE(dev); 151 I6300State *d = WATCHDOG_I6300ESB_DEVICE(pdev); 152 153 i6300esb_debug("I6300State = %p\n", d); 154 155 i6300esb_disable_timer(d); 156 157 /* NB: Don't change d->previous_reboot_flag in this function. */ 158 159 d->reboot_enabled = 1; 160 d->clock_scale = CLOCK_SCALE_1KHZ; 161 d->int_type = INT_TYPE_IRQ; 162 d->free_run = 0; 163 d->locked = 0; 164 d->enabled = 0; 165 d->timer1_preload = 0xfffff; 166 d->timer2_preload = 0xfffff; 167 d->stage = 1; 168 d->unlock_state = 0; 169 } 170 171 /* This function is called when the watchdog expires. Note that 172 * the hardware has two timers, and so expiry happens in two stages. 173 * If d->stage == 1 then we perform the first stage action (usually, 174 * sending an interrupt) and then restart the timer again for the 175 * second stage. If the second stage expires then the watchdog 176 * really has run out. 177 */ 178 static void i6300esb_timer_expired(void *vp) 179 { 180 I6300State *d = vp; 181 182 i6300esb_debug("stage %d\n", d->stage); 183 184 if (d->stage == 1) { 185 /* What to do at the end of stage 1? */ 186 switch (d->int_type) { 187 case INT_TYPE_IRQ: 188 fprintf(stderr, "i6300esb_timer_expired: I would send APIC 1 INT 10 here if I knew how (XXX)\n"); 189 break; 190 case INT_TYPE_SMI: 191 fprintf(stderr, "i6300esb_timer_expired: I would send SMI here if I knew how (XXX)\n"); 192 break; 193 } 194 195 /* Start the second stage. */ 196 i6300esb_restart_timer(d, 2); 197 } else { 198 /* Second stage expired, reboot for real. */ 199 if (d->reboot_enabled) { 200 d->previous_reboot_flag = 1; 201 watchdog_perform_action(); /* This reboots, exits, etc */ 202 i6300esb_reset(DEVICE(d)); 203 } 204 205 /* In "free running mode" we start stage 1 again. */ 206 if (d->free_run) 207 i6300esb_restart_timer(d, 1); 208 } 209 } 210 211 static void i6300esb_config_write(PCIDevice *dev, uint32_t addr, 212 uint32_t data, int len) 213 { 214 I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev); 215 int old; 216 217 i6300esb_debug("addr = %x, data = %x, len = %d\n", addr, data, len); 218 219 if (addr == ESB_CONFIG_REG && len == 2) { 220 d->reboot_enabled = (data & ESB_WDT_REBOOT) == 0; 221 d->clock_scale = 222 (data & ESB_WDT_FREQ) != 0 ? CLOCK_SCALE_1MHZ : CLOCK_SCALE_1KHZ; 223 d->int_type = (data & ESB_WDT_INTTYPE); 224 } else if (addr == ESB_LOCK_REG && len == 1) { 225 if (!d->locked) { 226 d->locked = (data & ESB_WDT_LOCK) != 0; 227 d->free_run = (data & ESB_WDT_FUNC) != 0; 228 old = d->enabled; 229 d->enabled = (data & ESB_WDT_ENABLE) != 0; 230 if (!old && d->enabled) /* Enabled transitioned from 0 -> 1 */ 231 i6300esb_restart_timer(d, 1); 232 else if (!d->enabled) 233 i6300esb_disable_timer(d); 234 } 235 } else { 236 pci_default_write_config(dev, addr, data, len); 237 } 238 } 239 240 static uint32_t i6300esb_config_read(PCIDevice *dev, uint32_t addr, int len) 241 { 242 I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev); 243 uint32_t data; 244 245 i6300esb_debug ("addr = %x, len = %d\n", addr, len); 246 247 if (addr == ESB_CONFIG_REG && len == 2) { 248 data = 249 (d->reboot_enabled ? 0 : ESB_WDT_REBOOT) | 250 (d->clock_scale == CLOCK_SCALE_1MHZ ? ESB_WDT_FREQ : 0) | 251 d->int_type; 252 return data; 253 } else if (addr == ESB_LOCK_REG && len == 1) { 254 data = 255 (d->free_run ? ESB_WDT_FUNC : 0) | 256 (d->locked ? ESB_WDT_LOCK : 0) | 257 (d->enabled ? ESB_WDT_ENABLE : 0); 258 return data; 259 } else { 260 return pci_default_read_config(dev, addr, len); 261 } 262 } 263 264 static uint32_t i6300esb_mem_readb(void *vp, hwaddr addr) 265 { 266 i6300esb_debug ("addr = %x\n", (int) addr); 267 268 return 0; 269 } 270 271 static uint32_t i6300esb_mem_readw(void *vp, hwaddr addr) 272 { 273 uint32_t data = 0; 274 I6300State *d = vp; 275 276 i6300esb_debug("addr = %x\n", (int) addr); 277 278 if (addr == 0xc) { 279 /* The previous reboot flag is really bit 9, but there is 280 * a bug in the Linux driver where it thinks it's bit 12. 281 * Set both. 282 */ 283 data = d->previous_reboot_flag ? 0x1200 : 0; 284 } 285 286 return data; 287 } 288 289 static uint32_t i6300esb_mem_readl(void *vp, hwaddr addr) 290 { 291 i6300esb_debug("addr = %x\n", (int) addr); 292 293 return 0; 294 } 295 296 static void i6300esb_mem_writeb(void *vp, hwaddr addr, uint32_t val) 297 { 298 I6300State *d = vp; 299 300 i6300esb_debug("addr = %x, val = %x\n", (int) addr, val); 301 302 if (addr == 0xc && val == 0x80) 303 d->unlock_state = 1; 304 else if (addr == 0xc && val == 0x86 && d->unlock_state == 1) 305 d->unlock_state = 2; 306 } 307 308 static void i6300esb_mem_writew(void *vp, hwaddr addr, uint32_t val) 309 { 310 I6300State *d = vp; 311 312 i6300esb_debug("addr = %x, val = %x\n", (int) addr, val); 313 314 if (addr == 0xc && val == 0x80) 315 d->unlock_state = 1; 316 else if (addr == 0xc && val == 0x86 && d->unlock_state == 1) 317 d->unlock_state = 2; 318 else { 319 if (d->unlock_state == 2) { 320 if (addr == 0xc) { 321 if ((val & 0x100) != 0) 322 /* This is the "ping" from the userspace watchdog in 323 * the guest ... 324 */ 325 i6300esb_restart_timer(d, 1); 326 327 /* Setting bit 9 resets the previous reboot flag. 328 * There's a bug in the Linux driver where it sets 329 * bit 12 instead. 330 */ 331 if ((val & 0x200) != 0 || (val & 0x1000) != 0) { 332 d->previous_reboot_flag = 0; 333 } 334 } 335 336 d->unlock_state = 0; 337 } 338 } 339 } 340 341 static void i6300esb_mem_writel(void *vp, hwaddr addr, uint32_t val) 342 { 343 I6300State *d = vp; 344 345 i6300esb_debug ("addr = %x, val = %x\n", (int) addr, val); 346 347 if (addr == 0xc && val == 0x80) 348 d->unlock_state = 1; 349 else if (addr == 0xc && val == 0x86 && d->unlock_state == 1) 350 d->unlock_state = 2; 351 else { 352 if (d->unlock_state == 2) { 353 if (addr == 0) 354 d->timer1_preload = val & 0xfffff; 355 else if (addr == 4) 356 d->timer2_preload = val & 0xfffff; 357 358 d->unlock_state = 0; 359 } 360 } 361 } 362 363 static uint64_t i6300esb_mem_readfn(void *opaque, hwaddr addr, unsigned size) 364 { 365 switch (size) { 366 case 1: 367 return i6300esb_mem_readb(opaque, addr); 368 case 2: 369 return i6300esb_mem_readw(opaque, addr); 370 case 4: 371 return i6300esb_mem_readl(opaque, addr); 372 default: 373 g_assert_not_reached(); 374 } 375 } 376 377 static void i6300esb_mem_writefn(void *opaque, hwaddr addr, 378 uint64_t value, unsigned size) 379 { 380 switch (size) { 381 case 1: 382 i6300esb_mem_writeb(opaque, addr, value); 383 break; 384 case 2: 385 i6300esb_mem_writew(opaque, addr, value); 386 break; 387 case 4: 388 i6300esb_mem_writel(opaque, addr, value); 389 break; 390 default: 391 g_assert_not_reached(); 392 } 393 } 394 395 static const MemoryRegionOps i6300esb_ops = { 396 .read = i6300esb_mem_readfn, 397 .write = i6300esb_mem_writefn, 398 .valid.min_access_size = 1, 399 .valid.max_access_size = 4, 400 .endianness = DEVICE_LITTLE_ENDIAN, 401 }; 402 403 static const VMStateDescription vmstate_i6300esb = { 404 .name = "i6300esb_wdt", 405 /* With this VMSD's introduction, version_id/minimum_version_id were 406 * erroneously set to sizeof(I6300State), causing a somewhat random 407 * version_id to be set for every build. This eventually broke 408 * migration. 409 * 410 * To correct this without breaking old->new migration for older 411 * versions of QEMU, we've set version_id to a value high enough 412 * to exceed all past values of sizeof(I6300State) across various 413 * build environments, and have reset minimum_version_id to 1, 414 * since this VMSD has never changed and thus can accept all past 415 * versions. 416 * 417 * For future changes we can treat these values as we normally would. 418 */ 419 .version_id = 10000, 420 .minimum_version_id = 1, 421 .fields = (const VMStateField[]) { 422 VMSTATE_PCI_DEVICE(dev, I6300State), 423 VMSTATE_INT32(reboot_enabled, I6300State), 424 VMSTATE_INT32(clock_scale, I6300State), 425 VMSTATE_INT32(int_type, I6300State), 426 VMSTATE_INT32(free_run, I6300State), 427 VMSTATE_INT32(locked, I6300State), 428 VMSTATE_INT32(enabled, I6300State), 429 VMSTATE_TIMER_PTR(timer, I6300State), 430 VMSTATE_UINT32(timer1_preload, I6300State), 431 VMSTATE_UINT32(timer2_preload, I6300State), 432 VMSTATE_INT32(stage, I6300State), 433 VMSTATE_INT32(unlock_state, I6300State), 434 VMSTATE_INT32(previous_reboot_flag, I6300State), 435 VMSTATE_END_OF_LIST() 436 } 437 }; 438 439 static void i6300esb_realize(PCIDevice *dev, Error **errp) 440 { 441 I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev); 442 443 i6300esb_debug("I6300State = %p\n", d); 444 445 d->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, i6300esb_timer_expired, d); 446 d->previous_reboot_flag = 0; 447 448 memory_region_init_io(&d->io_mem, OBJECT(d), &i6300esb_ops, d, 449 "i6300esb", 0x10); 450 pci_register_bar(&d->dev, 0, 0, &d->io_mem); 451 } 452 453 static void i6300esb_exit(PCIDevice *dev) 454 { 455 I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev); 456 457 timer_free(d->timer); 458 } 459 460 static void i6300esb_class_init(ObjectClass *klass, void *data) 461 { 462 DeviceClass *dc = DEVICE_CLASS(klass); 463 PCIDeviceClass *k = PCI_DEVICE_CLASS(klass); 464 465 k->config_read = i6300esb_config_read; 466 k->config_write = i6300esb_config_write; 467 k->realize = i6300esb_realize; 468 k->exit = i6300esb_exit; 469 k->vendor_id = PCI_VENDOR_ID_INTEL; 470 k->device_id = PCI_DEVICE_ID_INTEL_ESB_9; 471 k->class_id = PCI_CLASS_SYSTEM_OTHER; 472 dc->reset = i6300esb_reset; 473 dc->vmsd = &vmstate_i6300esb; 474 set_bit(DEVICE_CATEGORY_WATCHDOG, dc->categories); 475 dc->desc = "Intel 6300ESB"; 476 } 477 478 static const TypeInfo i6300esb_info = { 479 .name = TYPE_WATCHDOG_I6300ESB_DEVICE, 480 .parent = TYPE_PCI_DEVICE, 481 .instance_size = sizeof(I6300State), 482 .class_init = i6300esb_class_init, 483 .interfaces = (InterfaceInfo[]) { 484 { INTERFACE_CONVENTIONAL_PCI_DEVICE }, 485 { }, 486 }, 487 }; 488 489 static void i6300esb_register_types(void) 490 { 491 type_register_static(&i6300esb_info); 492 } 493 494 type_init(i6300esb_register_types) 495